Heavy duty diesel engine life, or time to rebuild, has historically been linked directly to piston ring, cylinder liner and/or crank shaft bearing life (referred to as “bearings” for sake of simplicity). Engine design parameters require that these engine components be lubricated, typically with a film lubricant of oil separating these engine components to prevent or minimize direct metal to metal contact. With oil lubricating these bearing surfaces, the principal mechanism associated with engine wear is not metal to metal contact or frictional wear. Instead the primary diesel engine wear component influencing engine life is corrosive wear caused by sulfur and nitrogen containing acids that are formed as products of combustion. One estimate is that more than 70% of heavy duty diesel engine wear is caused by such combustion acid metal corrosion.
Control of diesel engine corrosive wear has historically been accomplished through the inclusion of basic or alkaline chemicals dissolved or suspended in the engine oil that are used to rapidly neutralize combustion acid upon contact with the acid molecules. There have been proposals in the prior art to release alkaline or basic chemicals into the oil or otherwise neutralize acids utilizing a housing arranged along an oil circuit such as is disclosed in U.S. Pat. No. 5,459,074 to Muoni; U.S. Pat. No. 5,718,258 to Lefebvre et al.; U.S. Pat. No. 5,068,044 to Brownawell et al.; U.S. Pat. No. 5,069,799 to Brownawell et al.; U.S. Pat. No. 5,225,081 to Brownawell et al.
Any attempt at implementing acid neutralizing technology into a commercial practical engine oil circuit needs to accommodate several important factors while at the same time providing a sufficiently inexpensive filter cartridge for maintenance intervals to make it commercially practical for fleet managers and the like. As will be appreciated with an understanding of the present invention, these issues have not heretofore been adequately satisfied by the prior art.